By Alistair Scrutton and Aija Krutaine
RIGA (Reuters) - The European Union is ready to step up sanctions on Russia over the Ukraine conflict, but its priority is to bolster a fragile ceasefire agreed in Minsk, EU foreign policy chief Federica Mogherini said on Friday.
Mogherini, attending a meeting of EU foreign ministers in Latvia, said the need now was to strengthen ceasefire monitors from the Organization for Security and Co-operation in Europe (OSCE), a rights and security watchdog.
Despite some signs of improvement in eastern Ukraine since a new ceasefire was agreed last month, there was no question of the EU easing sanctions now, she said.
"They will not be lifted until something really good happens on the ground and on the other side we are always ready to increase the pressure if needed," Mogherini told a conference.
"So far the ceasefire has been starting, not perfect with some violations still, but for sure the trend is a positive one," she added. "We need ... to strengthen the OSCE mission that is on the ground now."
The EU has joined the United States in imposing sanctions on Russia but has found it increasingly difficult to agree on tougher measures as many member states rely heavily on Russia for energy.
The truce has eased pressure for new sanctions, but the EU must decide soon whether to extend economic curbs on Russia that expire in July.
Lithuanian Foreign Minister Linas Linkevicius, an EU hawk on Russia, said extending sanctions to the end of the year was "the least we can do".
"Everyone is for unity but you know unity to do nothing is not for me. I don't like it. So we have to be united on doing something," he told reporters.
Violence is continuing in eastern Ukraine despite the ceasefire accord, which calls for the withdrawal of heavy weapons.
Russia denies accusations by Ukraine and Western governments that it has been sending troops and weapons to support separatists.
Mogherini warned against a return to a Cold War mentality.
"Any attempt to go back to a logic of confrontation that recalls the 50s ... is not a European logic. And if someone else in Moscow falls into that trap or promotes that trap it is not for us to follow that mistake."
Britain's Foreign Minister Philip Hammond said in Warsaw on Friday the EU would prepare possible new sanctions on Russia that could be imposed quickly if the Minsk deal was broken.